Germicidal compositions and wipes and methods of making

Abstract

A method of making a clear, homogeneous aqueous antimicrobial composition, the method including: (a) mixing an anionic surfactant with a water-soluble cationic quaternary ammonium (QAC) surfactant in an aqueous medium under conditions effective to form an anionic-rich catanionic mixture that is clear and free of visible precipitate and retains antimicrobial efficacy, wherein: (i) total surfactant concentration is greater than 0.1 wt. %; (ii) weight or molar ratio of anionic to cationic surfactant is greater than 1; and (iii) pH of the medium is greater than or equal to 7 and adjusted with a pH-adjusting agent; and (b) adding an aqueous medium carrier comprising water and, optionally, one or more antimicrobial materials.

What is claimed is: 
     
         1 . A method of making a clear, homogeneous aqueous antimicrobial composition, the method comprising:
 (a) mixing an anionic surfactant with a water-soluble cationic quaternary ammonium (QAC) surfactant in an aqueous medium under conditions effective to form an anionic-rich catanionic mixture that is clear and free of visible precipitate and retains antimicrobial efficacy, wherein:
 (i) total surfactant concentration is greater than 0.1 wt. %; 
 (ii) weight or molar ratio of anionic to cationic surfactant is greater than 1; and 
 (iii) pH of the medium is greater than or equal to 7 and adjusted with a pH-adjusting agent; and 
   (b) adding an aqueous medium carrier comprising water and, optionally, one or more antimicrobial materials.   
     
     
         2 . The method of  claim 1 , wherein the antimicrobial material is added to the homogeneous aqueous antimicrobial composition and is selected from the group consisting of metal ion containing compounds, aromatic alcohols, lower alkanols, peroxides, essential oils, salts, organic acid salts, phenols, antibiotics, water-soluble bisbiguanides, and combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein the pH-adjusting agent is selected from potassium hydroxide, sodium hydroxide, calcium hydroxide, phosphate, carbonate, bicarbonate, laurates, and combinations thereof. 
     
     
         4 . The method of  claim 1 , wherein the total surfactant concentration is from about 0.1 wt. % to about 20 wt. % and the anionic to cationic weight or molar ratio is in a range from about 1 to 30. 
     
     
         5 . The method of  claim 1 , wherein the cationic surfactant comprises an alkyl-QAC and the alkyl group includes 8 to 18 carbon atoms. 
     
     
         6 . The method of  claim 5 , wherein the alkyl-QAC is selected from alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl ethyl benzyl ammonium chloride, didecyl dimethyl ammonium chloride, dialkyl dimethyl ammonium chloride, benzethonium chloride, cetylpyridinium chloride, and mixtures thereof. 
     
     
         7 . The method of  claim 1 , wherein the cationic surfactant is selected from the group consisting of a polymeric QAC, an organosilane QAC, and a mixture thereof. 
     
     
         8 . The method of  claim 1 , wherein the cationic surfactant comprises a polymeric QAC comprising one or more polyquaterniums. 
     
     
         9 . The method of  claim 1 , wherein the cationic surfactant comprises an ethoxylated quaternary ammonium compound of the formula methyl poly(oxyethylene)C8-C18 alkyl ammonium chloride, wherein the poly(oxyethylene) includes 2-15 oxyethylene units. 
     
     
         10 . The method of  claim 1 , wherein the cationic surfactant comprises a mixture of any two or more of the following:
 (i) a QAC having at least one alkyl chloride, wherein the alkyl group includes from 8 to 18 carbon atoms, and the alkyl chloride is selected from the group consisting of alkyl dimethyl benzyl ammonium chloride, alkyl dimethyl ethyl benzyl ammonium chlorides, and combinations thereof;   (ii) at least one polymeric QAC having one or more polyquaterniums;   (iii) at least one ethoxylated QAC of the formula methyl poly(oxyethylene)C8-C18 alkyl ammonium chloride, wherein the poly(oxyethylene) includes an oxyethylene content from 2 to 15; and   (iv) at least one organosilane QAC selected from the group consisting of 3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride and 3-(trihydroxysilyl) propyl dimethyl octadecyl ammonium chloride.   
     
     
         11 . The method of  claim 1 , wherein the anionic surfactant is selected from sulfonates, sulfates, fatty acid salts having 4-22 carbon atoms, and combinations thereof. 
     
     
         12 . The method of  claim 1 , further comprising the step of adding a member selected from the group consisting of a saponified natural fat, coconut oil, corn oil, cottonseed oil, lard, olive oil, palm oil, palm kernel oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, sunflower oil, tallow, and mixtures thereof. 
     
     
         13 . The method of  claim 1 , further comprising the step of adding essential oil or essential oil derivatives selected from the group consisting of thyme oil, eucalyptus oil, cinnamon oil, orange oil, lemon oil, clove oil, lime oil, rosemary oil, citronella oil, cedar wood oil, camphor oil, calamus oil, geranium oil, lavender, lemongrass oil, peppermint oil, vetiver oil, palmarosa oil, nutmeg oil, and combinations thereof. 
     
     
         14 . The method of  claim 1 , further comprising the step of adding a nonionic surfactant. 
     
     
         15 . The method of  claim 14 , wherein the nonionic surfactant is selected from alcohol ethoxylates, alcohol propoxylates, alkyl polyglucosides, amine oxides, and mixtures thereof. 
     
     
         16 . The method of  claim 1 , further comprising the step of adding 1-80 wt. % of an evaporation enhancer selected from silicone-based materials, ketones, lower alkanols, and mixtures thereof. 
     
     
         17 . The method of  claim 16 , wherein the lower alkanols are ethanol, n-propanol, isopropanol, or mixtures thereof. 
     
     
         18 . The method of  claim 1 , further comprising the step of adding an organic acid selected from lactic acid, citric acid, salicylic acid, benzoic acid, 2-furan carboxylic acid, or mixtures thereof. 
     
     
         19 . A method for maintaining antimicrobial activity of a quaternary ammonium compound (QAC) by reducing its binding to a cellulosic substrate, the method comprising:
 (a) forming an anionic-rich catanionic mixture that is clear and free of visible precipitate and that retains antimicrobial efficacy by mixing at least one anionic surfactant with water-soluble cationic QACs in an aqueous carrier to form a composition, wherein the total surfactant concentration is greater than 0.1 wt. %; the weight or molar ratio of the anionic surfactant to the QAC is greater than 1 and the pH of the composition is greater than or equal to 7; and   (b) applying the composition to the cellulosic substrate, whereby the binding of the QAC to the cellulosic substrate is reduced as compared to a composition lacking the at least one anionic surfactant.   
     
     
         20 . The method of  claim 19 , wherein the cellulosic substrate is a cotton wipe or a synthetic wipe and the at least one anionic surfactant is selected from the group consisting of sodium lauryl sulfate and potassium laurate.